• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.343-350
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• 2013

The objectives of this study were to estimate the potential biomass yield by using the biomass conversion index and evaluate the potential energy production by using the energy conversion index of biomass. Estimating the total biomass yield in Korea showed 9,646.3 thousand tons produced in 2012. Subsequent evaluation of the potential energy production using the estimated biomass yield in 2012 indicated that the calorific values were varied from 3,800 to 4,500 kcal $kg^{-1}$ for crop- and from 4,100 to 4,300 kcal $kg^{-1}$ for woody-based biomass, respectively. Among the examined biomass materials, the pruned branch of a nut tree appeared to be the greatest in bio-energy production showing 6,300 kcal $kg^{-1}$ in calorific value. Total potential energy production from agricultural by-products was estimated approximately at 3,966,000 TOE. Among the agricultural by-products examined, rice straw showed the greatest energy production potential being at 2,321,000 TOE. Furthermore, it might contribute to establishing the countermeasures of biomass utility in agricultural sector based on regional distribution chart of the potential biomass and energy yields in Korea.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.200-203
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• 2008

The objective of this study is to produce the $CO_2$ (carbon dioxide) absorption map using KOMPSAT-2 imagery. For estimating the amount of $CO_2$ absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated by the crown width extracted from KOMPSAT-2 imagery. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC (Intergovernmental Panel on Climate Change) guideline, was used to convert the stand biomass into the amount of $CO_2$ absorption. Thereafter, the KOMPSAT-2 imagery was classified with the SBC (segment based classification) method in order to quantify $CO_2$ absorption by tree species. As a result, the map of $CO_2$ absorption was produced and the amount of $CO_2$ absorption was estimated by tree species.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.39-45
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• 2010

Quantification of carbon absorption and understanding the human induced land use changes (LUC) forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by LUC through remote sensing technology. The Landsat imagery four time periods was classified with the hybrid classification method in order to quantify carbon absorption by LUC. Thereafter, for estimating the amount of carbon absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated with the crown width extracted from digital forest cover type map. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC guideline, was used to convert the stand biomass into the amount of carbon absorption. Total carbon absorption has been modeled by taking areal estimates of LUC of four time periods and carbon factors for land use type and standing biomass. Results of this study, through LUC suggests that over a period of construction, 7.10 % of forest and 9.43 % of barren were converted into urban. In the conversion process, there has been a loss of 6.66 t/ha/y (7.94 %) of carbon absorption from the study area.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.244.2-244.2
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• 2010

Biological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide into monomeric sugars. In this study, dilute sulfuric acid used as a catalyst for the pretreatment of rapeseed straw. Hydrolysis can be performed enzymatically, and with dilute or concentrate mineral acids. Dilute-acid hydrolysis of rapeseed straw was optimized through the utilization of combined severity. Evaluation criteria for optimization of the pretreatment conditions were based on high xylose recovery and low inhibitor contents in the hydrolyzates. In addition, this paper reports the compositional analysis of hydrolyzate liquors and solid residues, xylose and glucose mass balance closures, and digestibility results of the acid pretreated rapeseed straw.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.324-330
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• 2009

The objective of this study is to estimate the carbon sequestration in forest stands using KOMPSAT-2 imagery. For estimating the amount of carbon sequestration, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated by the crown width extracted from KOMPSAT-2 imagery. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the Intergovernmental Panel on Climate Change (IPCC) guideline, was used to convert the stand biomass into the amount of carbon sequestration. Thereafter, the KOMPSAT-2 imagery was classified with the segment based classification (SBC) method in order to quantify carbon sequestration by tree species. This approach, estimating the amount of carbon sequestration for certain species in stand, can be available to extend plot-based carbon sequestration to stand-based carbon sequestration.

• Mycobiology
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• v.51 no.4
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• pp.239-245
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• 2023

Xylanase has been applied in various sectors, such as biomass conversion, paper, pulp, textiles, and pharmaceutical industries. This study aimed to isolate and screen potential xylanase-producing fungi from the soil of Suphan Buri Province, Thailand. Fifteen fungi were isolated, and their xylanase activities were tested by the qualitative method. The result showed that isolate SP3, SP10 and SP15 gave high xylanase activity with potency index (PI) of 2.32, 2.01 and 1.82, respectively. These fungi were selected for the xylanase quantitative test, isolate SP10 performed the highest xylanase activity with 0.535 U/mL. Through molecular methods using the 𝛽-tubulin gene, isolate SP10 was identified as Penicillium menonorum. The xylanase characteristics from P. menonorum SP10 were determined, including the xylanase isoforms and the optimum pH and temperature. The xylanase isoforms on SDS-PAGE indicated that P. menonorum SP10 produced two xylanases (45 and 54 kDa). Moreover, its xylanase worked optimally at pH 6 and 55 ℃ while reaching 61% activity at 65 ℃. These results proposed P. menonorum SP10 as a good candidate for industrial uses, especially in poultry feed and pulp industries, to improve yield and economic efficiency under slightly acidic and high-temperature conditions.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.198-221
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• 2021

After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO₂ exchange of old-growth forests is theoretically near zero; however, it can be a CO₂ sink or source depending on the intervention of disturbance or management. In this study, we report the CO₂ budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO₂ neutral as theoretically known? and (2) can we explain the dynamics of CO₂ budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO₂ flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO₂ but averaged to be a week CO₂ source (and turning to a moderate CO₂ source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R²=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO₂ source. To properly understand and interpret the long-term CO₂ budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.